PLL for low frequencies

[vaka85]

Hello,

I'm looking for a PLL working with analog inputs and frequency of 1 MHz.
It seems impossibile to find!!

The only one that I've found it's ne560, it would be perfect, but it's very old and impossible to find...
Do you know any similar model?

Thanks

 

[volker_muehlhaus]

Have you looked at the 4046 CMOS device, which was available from many different manufacturers?
It has a built-in VCO, but you can also use the PLL with external signals.

 

[vaka85]

yes, I've seen it, but it seems to work with higher frequencies than 1 MHz.
And, also, are you sure that works with analogue inputs?

 

[dick_freebird]

Why do you insist that it -only- work below 1MHz?

PLLs with low frequency sinusoidal inputs will have crappy
phase noise. You would be well off to square it up (in a
clean close-in to source location) and then lock to the
squarest edge you can, if you care about purity.

Such low frequecies are probably "off-application" for
many modern PLLs but that does not mean they are
unusable, just that nobody cares about that use.

 

[vaka85]

I have a sinusoidal signal of 1 MHz, and in the datasheet I see "minimum frequency = 7 MHz"... That's why I'm not sure.

Old ne560 would be perfect for my need, but it seems impossible to find something similar..

that does not mean they are unusable, just that nobody cares about that use.

If a datasheet speaks about minimum frequency, I assume that it doesn't work under it! Or works bad!

 

[volker_muehlhaus]

and in the datasheet I see "minimum frequency = 7 MHz"...

But that is only for the VCO part (VCO tuning range with the component value examples given there).

If you look at the description & design of the phase comparators, there should be no lower frequency limit.

 

[vaka85]

ok.. But how can I understand if a model is suitable for analog inputs?

 

[mehdinoormohammadi]

Hi Dear,

I'm looking for a PLL to work with analog input frequency of 15KHz, so I want to generate a 64 times of 15KHz at the PLL output.
Thanks